Hormone replacement therapy does increase cancer risk

Cancer Research UK is deeply concerned for women’s health amid headlines that taking Hormone Replacement Therapy (HRT) is safe, based on research presented to the American Society for Reproductive Medicine in Baltimore, USA on Monday (yesterday).

As reported, the research, from New York University, only looked at a very small number of women who had used HRT for an average of 14 years and found that women who took HRT did not have an increased risk of cancer, heart disease or diabetes.

But there is strong evidence from several much larger studies that HRT can cause some types of cancer including breast, ovarian and in some cases womb. This includes the million women study, run by Cancer Research UK scientists, which has shown that different types of HRT can increase the risk of different cancers.

More on our blog: No, HRT isn’t ‘harmless’

The million women study is a national study of women’s health involving one million women over the age of 50. It’s investigating how various reproductive and lifestyle factors affect women’s health. The research has looked at how HRT affects cancer risk in women.

The UK, European and US guidelines all acknowledge the risks and generally advise that women should take as low a dose of HRT as possible, and for as short a time as possible.

Professor Dame Valerie Beral, Cancer Research UK’s epidemiology expert said: “More women will get cancer if the use of HRT increases. We have looked at the overall evidence and what that shows is a clear picture that HRT can increase the risk of developing both breast and ovarian cancer, even if it is used for only a short time.

“HRT is an effective treatment for menopausal symptoms but women need to be aware of the real risks when making the decision to use HRT, and should discuss their options with their doctor.”

Harpal Kumar, Cancer Research UK’s chief executive, said: “We are very concerned about the coverage of this story in the media yesterday. We know that hormone therapy does increase a person’s risk of developing cancer. And it’s wrong to claim definitive evidence based on one small study.

“The overwhelming body of evidence including the results of the million women study show women who are using combined hormone therapy double their risk of breast cancer compared to those not using it. How the risks and benefits stack up for everyone will be different. It’s important that women have good quality information to help them come to the right decision for them.”